U.S. patent application number 12/157508 was filed with the patent office on 2008-12-18 for sound collector and sound recorder.
This patent application is currently assigned to Sony Corporation. Invention is credited to Eiichi Yamada.
Application Number | 20080310649 12/157508 |
Document ID | / |
Family ID | 40132346 |
Filed Date | 2008-12-18 |
United States Patent
Application |
20080310649 |
Kind Code |
A1 |
Yamada; Eiichi |
December 18, 2008 |
Sound collector and sound recorder
Abstract
A sound collector includes a first microphone unit and a second
microphone unit having a single directivity and being pivotally
supported in a manner that directions of directional axes of the
units are changeable in an identical flat plane and a switch to be
controlled in conjunction with the rotations of the first and the
second microphone units. Output signals of the first and the second
microphone units are outputted with channels of the signals being
exchanged or non-exchanged by the switch in accordance with an
angle formed by the directional axes.
Inventors: |
Yamada; Eiichi; (Tokyo,
JP) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,;KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
40132346 |
Appl. No.: |
12/157508 |
Filed: |
June 11, 2008 |
Current U.S.
Class: |
381/92 |
Current CPC
Class: |
H04R 5/027 20130101;
H04R 3/005 20130101 |
Class at
Publication: |
381/92 |
International
Class: |
H04R 3/00 20060101
H04R003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 13, 2007 |
JP |
P2007-155867 |
Claims
1. A sound collector comprising: A first microphone unit and a
second microphone unit having a single directivity and being
pivotally supported in a manner that directions of directional axes
of the units are changeable in an identical flat plane; and a
switch to be controlled in conjunction with the rotations of the
first and the second microphone units, wherein; output signals of
the first and the second microphone units are outputted with
channels of the signals being exchanged or non-exchanged by the
switch in accordance with an angle formed by the directional
axes.
2. The sound collector according to claim 1, wherein; output is
executed by causing the switch to execute either of exchange and
non-exchange of the channels, depending on whether the directional
axes of the first and the second microphone units are crossed or
not.
3. A sound recorder comprising: A first microphone unit and a
second microphone unit having a single directivity; a recording
media to record audio signals collected by the first and the second
microphone units; and a switch, wherein; the first and the second
microphone units are pivotally supported by the front portion of
the body of the recorder in a rotatable manner and directions of
directional axes of the first and the second microphone units
having a single directivity may be changeable in an identical flat
plane; the switch is controlled in conjunction with the rotations
of the first and the second microphone units; and output signals of
the first and the second microphone units are recorded to the
recording media with channels of the signals exchanged or
non-exchanged by the output of the switch, depending on whether the
directional axes of the first and the second microphone units are
crossed or not.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sound collector and a
sound recorder.
[0003] 2. Description of Related Art
[0004] Examples of portable stereo sound recorders include those in
which microphone units for collecting sounds are in an XY
arrangement. FIG. 8A is a plan view showing the arrangement of the
sound recorder of this type and the microphone units. A sound
recorder 10 has the shape of a rectangular parallelepiped of
approximately 70 mm (width).times.150 mm (depth).times.30 mm
(thickness), and the front thereof is provided with a pair of
microphone units 11L and 11R.
[0005] In this case, the microphone units 11L and 11R have
uni-directivity. It is preferable if the microphone units 11L and
11R are arrange such that diaphragms (not shown) thereof are
orthogonalized each other. However, practically it is difficult to
arrange to be orthogonal, therefore the microphone units 11L and
11R are arranged such that the sound collecting openings of the
units are sufficiently close to each other, and respective
directional axes 12L and 12R of the units are orthogonal to each
other in the identical horizontal plane.
[0006] With this configuration, as shown in FIG. 8B, regions 13L
and 13R become main sound collection ranges (directional ranges) of
the microphone units 11L and 11R, respectively, and high
sensitivity in the depth direction can be obtained, thereby
attaining stereo sounds and images having impression of depth. It
is therefore suitable for recording solo performance or the
like.
[0007] As a prior art document, the following may be referred to.
(Japanese Unexamined Patent Application Publication No.
2007-043510, Patent Document 1)
SUMMARY OF THE INVENTION
[0008] However, in the sensitivity characteristics shown in FIG.
8B, the sound collection range in the right-to-left direction is
somewhat narrow, and it is therefore unsuitable for sound
collection of the sound source expanding to right-to-left fields,
such as orchestra. For example, when recording in the situations
where a train running from the left remote location gets close to a
person, passes in front of the person, and then runs to the right
remote location, the impression of expanding fields cannot be
properly reproduced.
[0009] Accordingly, in an embodiment of the present invention, it
is desirable to solve the issue and also solve newly caused
issues.
[0010] The sound collector of one embodiment of the invention
includes first and second microphone units having uni-directivity
and being pivotally supported so that the directions of respective
directional axes may be changed in an identical plane, and a switch
controlled in conjunction with the rotations of the first and the
second microphone units. The output signals of the first and the
second microphone units are outputted by causing the switch to
execute either of exchange and non-exchange of the channels of
these output signals in accordance with an angle formed by the
directional axes.
[0011] According to embodiments of the present invention, the
directions of the directional axes of the first and the second
microphone units can be changed and the stereo mode and the
expansion field of sound can be set freely in accordance with the
sound source to be recorded, whereby allowing optimum sound
collection and sound recording in accordance with the sound
source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a plan view showing an embodiment of the present
invention;
[0013] FIGS. 2A to 2C are plan views for explaining the present
invention;
[0014] FIGS. 3A to 3C are plan views for explaining the directional
properties in the present invention;
[0015] FIG. 4 is a schematic diagram showing an embodiment of the
present invention;
[0016] FIGS. 5A and 5B are plan views for explaining the use
situations in an embodiment of the present invention;
[0017] FIGS. 6A to 6C are diagrams for explaining an embodiment of
a part of the mechanism and the circuit in the present
invention;
[0018] FIG. 7 is a diagram for explaining other embodiment of a
part of the circuit in the present invention; and
[0019] FIGS. 8A and 8B are plan views for explaining the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
1A. Configuration Example
Description of First Half
[0020] FIG. 1 is a plan view showing an example of the external
view when the present invention is applied to a portable stereo
sound recorder. Reference numeral 20 indicates the entire sound
recorder. The dot-dash line 20C indicates the center line in the
front-back direction of the recorder 20.
[0021] The sound recorder 20 is configured in the shape of
substantially a flat rectangular parallelepiped as a whole. A pair
of microphone units 21A and 21B are provided at the front portion
of the recorder by keeping a predetermined space, for example, 8 cm
to 9 cm, between the units.
[0022] In this case, the directivity of the microphone units 21A
and 21B is a uni-directivity. These microphone units 21A and 21B
are pivotally supported by pins 24 and 24, respectively in a
rotatable manner. As shown in FIGS. 2A to 2C, the directions of
directional axes 22A and 22B of the units 21A and 21B can be
changed, respectively, in the right-to-left direction in the
identical horizontal plane, including the center line 20C.
[0023] That is, FIG. 2A shows the case where the microphone units
21A and 21B are rotated such that the directional axes 22A and 22B
of the microphone units 21A and 21B are orthogonal to each other,
and the sound collecting openings of the microphone units 21A and
21B are sufficiently close to each other. The state shown in FIG.
2A corresponds to the state shown in FIG. 8A.
[0024] FIG. 2B shows the case where the microphone units 21A and
21B are rotated such that the directional axes 22A and 22B become
parallel to the center line 20C. FIG. 2C shows the case where the
microphone units 21A and 21B are rotated so that the directional
axes 22A and 22B are in the opening direction.
[0025] Based on the center line 20C in the front-back direction of
the recorder 20, for example, it is assumed as follows;
[0026] .theta.A is the angle formed between the directional axis
22A and the center line 20C. The counterclock direction is
positive.
[0027] .theta.B is the angle formed between the directional axis
22B and the center line 20C. The clock direction is positive.
[0028] Based on the assumptions, the three states can be expressed
as follows;
[0029] In the state shown in FIG. 2A,
.theta.A=.theta.B=-45.degree.;
[0030] In the state shown in FIG. 2B, .theta.A=.theta.B=0 (the
directional axes 22A and 22B are parallel); and
[0031] In the state shown in FIG. 2C,
.theta.A=.theta.B=60.degree..
Although not shown, it is arranged that the angles .theta.A and
.theta.B can be changed continuously and independently.
[0032] As shown in FIG. 1, switches 31A and 31B (described later)
are provided in conjunction with the microphone units 21A and 21B,
in the recorder 20.
[0033] With this configuration, when the microphone units 22A and
22B are in the state shown in FIG. 2A
(.theta.A=.theta.B=-45.degree.), which is the same state of that
shown in FIG. 8A, the directional properties shown in FIG. 3A can
be obtained, as similar with the case of FIG. 8B. Accordingly, the
regions 23A and 23B become the main sound collection ranges of the
microphone units 21A and 21B, respectively. Thus, because high
sensitivity in the depth direction can be achieved, stereo sounds
and images with an impression of depth may be obtained, thereby
making the units suitable for recording solo performance or the
like.
[0034] When the microphone units 22A and 22B are in the state shown
in FIG. 2B (.theta.A=.theta.B=0), the directional properties shown
in FIG. 3B can be obtained, and the regions 23A and 23B become the
main sound collection ranges of the microphone units 21A and 21B,
respectively. Therefore, although stereo mode is weak, very high
sensitivity with respect to the sounds from the front side can be
obtained, thereby making the units suitable for recording a sound
of a specific sound source.
[0035] When the microphone units 22A and 22B are in the state shown
in FIG. 2C (.theta.A=.theta.B=60.degree.), the directional
properties as shown in FIG. 3C can be obtained, and the regions 23A
and 23B become the main sound collection ranges of the microphone
units 21A and 21B, respectively. Therefore, stereo sounds and
images having impression of expanded in right and left can be
obtained, thereby making the units suitable for recording orchestra
performance or the like. Alternatively, when recording the
situations where a train gradually gets close from the left remote
location and passes in front of a person and runs to the right
remote location, impression of expansion may be properly
reproduced.
1B. Configuration Example
Description of Latter Part
[0036] If configurations are limited to the above, the following
problem in terms of audio signals (sound collection signals)
outputted from the microphone units 21A and 21B may occur, in the
case of FIG. 2A and in the case of FIG. 2C (and FIG. 2B).
[0037] That is, the state shown in FIG. 2A leads to the following
results:
[0038] The output of the microphone unit 21A is equal to the audio
signal of the right channel; and
[0039] The output of the microphone unit 21B is equal to the audio
signal of the left channel.
[0040] On the other hand, the state shown in FIG. 2C leads to the
following results:
[0041] The output of the microphone unit 21A is equal to the audio
signal of the left channel; and
[0042] The output of the microphone unit 21B is equal to the audio
signal of the right channel. Thus, the channels of the audio
signals to be outputted from the microphone units 21A and 21B are
reversed between the state shown in FIG. 2A and the state shown in
FIG. 2C.
[0043] Consequently, in the present invention, the circuit for
recording audio signals has, for example, the structure as shown in
FIG. 4. That is, audio signals SA and SB outputted from the
microphone units 21A and 21B are supplied via preamplifiers 32A and
32B to A/D (analog to digital) converter circuits 33A and 33B to be
converted into digital audio signals DA and DB, respectively. These
digital audio signals DA and DB are then supplied to preprocessing
circuits 41A and 41B, respectively.
[0044] In the preprocessing circuits 41A and 41B, the digital audio
signals DA and DB are subjected to, for example, limiter
processing, equalizer processing, and so-called SBM (super bit
mapping, registered trademark) processing in which quantization
noise is shifted to high frequency where grating on ear is avoided,
by use of noise shaping technique. The preprocessing circuits 41A
and 41B are integrated into a one-chip IC (integrated circuit) 34,
together with the following circuits 42 to 44.
[0045] The preprocessed digital audio signals DA and DB are written
sequentially in a buffer memory 43 by a write memory controller 42,
and the written digital audio signals DA and DB are read
sequentially by a read memory controller 44.
[0046] The switches 31A and 31B are provided to receive an on-off
control in conjunction with the rotations of the microphone units
21A and 21B (the changes in the angle .theta.A and the angle
.theta.B of the directional axes 22A and 22B), and the switch
outputs are supplied to the memory controller 44 as the control
signals of read addresses, respectively.
[0047] Subsequently, the digital audio signals DA and DB are read
from the memory 43 as follows.
[0048] Specifically, when the directional axes 22A and 22B are
crossed (for example, the state shown in FIG. 2A), these two
signals are read as follows:
[0049] The signal DA is the digital audio signal DR of the right
channel; and
[0050] The signal DB is the digital audio signal DL of the left
channel.
[0051] When the directional axes 22A and 22B are not crossed (for
example, the states shown in FIGS. 2B and 2C), these two signals
are read as follows:
[0052] The signal DA is the digital audio signal DL of the left
channel; and
[0053] The signal DB is the digital audio signal DR of the right
channel.
[0054] The read digital audio signals DL and DR of the left and
right channels are then written, namely recorded sequentially
through the controller 44 into a recording media, which is a
non-volatile memory 35 in this example.
[0055] The non-volatile memory 35 may be a memory contained in the
recorder 20, or alternatively may be a removable memory card. In
either case, by employing the USB (universal serial bus)
configuration, the contents of the memory 35 can be transferred to
and reproduced on an external personal computer or the like. When
the non-volatile memory is a memory card, the memory card can be
removed from the recorder 20 and reproduced by a personal computer
or the like.
[0056] In this manner, in the recorder 20 shown in FIG. 4, in
accordance with the angle formed between the directional axes 22A
and 22B of the microphone units 21A and 21B, the audio signals
outputted from the microphone units 21A and 21B are classified to
the digital audio signals of the left channel and the right
channel, and then written in the non-volatile memory 35.
[0057] Therefore, even if the microphone units 21A and 21B are in
the state shown in FIG. 2A or in the states shown in FIGS. 2B, or
2C, the digital audio signals DA and DB of the left and right
channels may be properly recorded in the non-volatile memory
35.
2. Summary
[0058] In accordance with the recorder 20, the correct states can
be recorded in a memory by the exchange of the channels of the
audio signals collected by the microphone units 21A and 21B between
the state shown in FIG. 2A and the state shown in FIG. 2C. Since
the directions of the directional axes 22A and 22B of the
microphone units 21A and 21B can be freely and continuously changed
between the state shown in FIG. 2A and the state shown in FIG. 2C
(via the state shown in FIG. 2B), the stereo mode and the degrees
of expansion can be freely set depending on the sound source to be
recorded, thereby allowing optimum sound collection and sound
recording.
[0059] For example, as shown in FIG. 5A, when recording is
performed with the recorder 20 set at the right position of a
concert hall, the sounds of concert performance from musical
instruments reach the microphone units 21A and 21B of the recorder
20 through various passages. Therefore, as shown in FIG. 2C, when
the directions of the directional axes 22A and 22B of the
microphone units 21A and 21B are symmetric with respect to the
center line 20C of the recorder 20, namely when .theta.A=.theta.B,
the microphone unit 21B may collect and record more reflected sound
components from the right wall surface than the microphone unit
21A.
[0060] However, the recorder 20 allows the directions of the
directional axes 22A and 22B of the microphone units 21A and 21B to
be set independently. Accordingly, in the case of the situation
shown in FIG. 5A, by setting directions of the directional axes 22A
and 22B of the microphone units 21A and 21B as those as shown in
FIG. 5B, the sound components reflected from the right wall surface
may be reduced and recording with a appropriate left/right sound
balance becomes possible.
3. Examples of Mechanism of Microphone Units and Switches, which
Move in Conjunction with Each Other
[0061] FIGS. 6A to 6C show one example of the mechanisms between
the microphone units 21A and 21B and the switches 31A and 31B,
which move in conjunction with each other. Since the relation
between the microphone units 21A and the switch 31A is the same as
the relation between the microphone unit 21B and the switch 31B,
FIGS. 6A to 6C exemplify only the relation between the microphone
unit 21A and the switch 31A. Further, directions of the directional
axis 22A of the microphone unit 21A in FIGS. 6A, 6B and 6C
corresponds to those in FIGS. 2C, 2B to 2A, respectively.
[0062] In FIGS. 6A to 6C, a convex portion 211 is integrally formed
with the circumferential surface of the back portion of the
microphone unit 21A along the rotating direction. At the position
facing to the back portion of the microphone unit 21A, for example,
a micro switch is provided as the switch 31A, and an actuator 311
of the switch 31A is provided so as to correspond to the convex
portion 211. For example, the microphone switch 31A may be a normal
open switch.
[0063] One input terminal of a NOR circuit 32 is pulled up by a
resistor R31, and the switch 31A is connected between the input
terminal and the grounding. The microphone unit 21B and the switch
31B are similarly configured and connected to the NOR circuit
32.
[0064] With this configuration, in the state shown in FIGS. 6A and
6B, that is, in the state where the directional axis 22A of the
microphone unit 21A does not cross with the center axis 20C
(.theta.A.gtoreq.0), the convex portion 211 does not press the
actuator 311, and accordingly the switch 31A is set to be the off
state and the output voltage VA of the switch 31A becomes "H"
level.
[0065] On the other hand, in the state shown in FIG. 6C, that is,
in the state where the directional axis 22A of the microphone unit
21A crosses with the center axis 20C (.theta.A<0), the convex
portion 211 presses the actuator 311, and accordingly the switch
31A is set to be the on state, and the output voltage VA becomes
"L" level.
[0066] The output voltage VB of the switch 31B becomes either "H"
level or "L" level in accordance with the angle .theta.B of the
directional axis 22B of the microphone unit 21B.
[0067] Accordingly, when the directional axes 22A and 22B of the
microphone units 21A and 21B are in the state shown in FIG. 2A, an
output signal S32 of the NOR circuit 32 becomes "H" level, whereas
in the state shown in FIG. 2B or 2C, the output signal S32 of the
NOR circuit 32 becomes "L" level. Thus, by supplying the NOR signal
S32 to the memory controller 44 as read control signal, as
described in the 1B, the audio signals SA and SB outputted from the
microphone units 21A and 21B may be properly recorded in the
non-volatile memory 35, as the digital audio signal DL or DR of the
left or right channel.
4. Other Examples
[0068] FIG. 7 shows other example of the configuration that
prevents the channels of audio signals from being reversed due to
the directions of the directional axes 22A and 22B of the
microphone units 21A and 21B. That is, in this example, variable
resistors 33A and 33B in conjunction with the rotations of the
microphone units 21A and 21B, respectively are provided. The output
audio signal SA of the microphone unit 21A is supplied to one
terminal (A) of each of the variable resistors 33A and 33B, and the
output audio signal SB of the microphone unit 21B is supplied to
the other terminal B of each of the variable resistors 33A and
33B.
[0069] The output signals of the needles of the variable resistors
33A and 33B are extracted as the audio signals SL and SR of the
left and right channels, respectively. In this example, even if the
directions of the directional axes 22A and 22B of the microphone
units 21A and 21B are changed, channel is not reversed while
reading is performed in the memory controller 44.
[0070] With this configuration, when the microphone units 21A and
21B are in the state shown in FIG. 2A, the signals SB and SA on the
terminals (B) side of the variable resistors 33A and 33B are
extracted as the signals SL and SR, respectively, and the extracted
signals serve as the audio signals of the left and right channels,
respectively.
[0071] When the microphone units 21A and 21B are in the state shown
in FIG. 2C, the signals SA and SA on the terminals (A) side of the
variable resistors 33A and 33B are extracted as the signals SL and
SR, and the extracted signals serve as the audio signals of the
left and right channels.
[0072] When the microphone units 21A and 21B are in the state shown
in FIG. 2B, mixed signals consisting of the signals on the
terminals (A) side and the terminal (B) side of the variable
resistors 33A and 33B are extracted as signals SL and SR.
[0073] In addition, the directions of the directional axes 22A and
22B of the microphone units 21A and 21B may be continuously
changed, and correspondingly the contents of the output audio
signals SL and SR (the signals SA and SB) of the variable resistors
33A and 33B change continuously, thereby allowing the impression of
expansion and stereo mode to be continuously changed.
5. Others
[0074] In the example shown in FIG. 4, when microphone units are in
the state shown in FIG. 2A, the controller 44 switches the
addresses when the digital audio signals DL and DR are read from
the memory 43, thereby preventing the inversion of the right and
left channels. Alternatively, the controller 42 may switch the
addresses when the digital audio signals DA and DB are written in
the memory 43, thereby preventing the inversion of the right and
left channels. Further, the inversion of the right and left
channels may be prevented by switching the signal lines from the
microphone units 21A and 21B to the controller 42.
[0075] When one of the microphone units 21A and 21B is rotated, the
directions of the directional axes 22A and 22B may be
correspondingly changed to satisfy ".theta.A=.theta.B". Further, a
non-directional microphone unit may be arranged between the
microphone units 21A and 21B, and its output audio signals may be
distributed to the right and left channels, in order to avoid
so-called lack of middle range.
[0076] Further, the directional axes 22A and 22B of the microphone
units 21A and 21B may have an elevation angle or a depression
angle. When the voice and sounds of an object are
collected/recorded by mounting these units on a movie camera, the
zooming mechanism may operate in conjunction with the rotation
mechanism of the microphone units 21A and 21B, so that the angle of
views and directional properties while capturing images match. In
other words, these two units may be brought into the state shown in
FIG. 2A at telescopic imaging, and to the state shown in FIG. 2C at
wide-angle imaging.
LIST OF ABBREVIATIONS
[0077] A/D: Analog to Digital
[0078] IC: Integrated Circuit
[0079] SBM: Super Bit Mapping (registered trademark)
[0080] USB: Universal Serial Bus
[0081] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
[0082] The present document contains subject matter related to
Japanese Patent Application No. 2007-155867 filed in the Japanese
Patent Office on Jun. 13, 2007, the entire content of which being
incorporated herein by reference.
* * * * *